Continuous electrophoresis apparatus with laminated wick electrodes



March 24, 1959 E. DURRUM ETAL 2,879,217

CONTINUOUS ELECTROPHORESIS APPARATUS WITH LAMINATED WICK ELECTRODES Filed June 7, 1956 3 Sheets-Sheet 2 March 24, 1959 E. L. DURRUM ETAL 2,879,217

CONTINUOUS ELECTROPHORESIS APPARATUS WITH LAMINATED WICK ELEcTRoDEs Filed June 7, 1956 3 Sheets-Sheet 3 4 EMMETT L. Dumm/M e' EDWARD G. P/CKELS :lz-113-4- /NvE/vrops United States Patent O CONTINUOUS ELECTROPHORESIS APPARATUS WITH LAMINATED WICK ELECTRODES Emmett L. Durrum, San Francisco, and Edward G.

Pickels, Atherton, Calif., assignors to Beckman Instruments, Inc., Fullerton, Calif., a corporation of Cahfornia Application June 7, 1956, serial No. 589,936 '12 claims. (ci. 204-299) This invention relates generally to a continuous electrophoresis apparatus.

Generally, in continuous electrophoresis, separation of components of a sample containing the same is accomplished by superposing an electric eld at some angle to the ow of a background electrolyte which has the sample applied thereto. Ordinarily, the electrolyte ows by gravity down an anticonvection medium or curtain. The mixture which is to be separated is fed into the background electrolyte and. flows downward in a narrow band in the absence of applied ield. The separationof the mixture under the influence of the electric eld is in accordance with the mobility of the various components under the given conditions.

In many apparatuses, a hanging sheet of filter paper serves as an anticonvection medium` or curtain. Electrolyte is suitably fed onto the sheet near the upper margin, for example, feed wicks may be employed. In other apparatus the upper portion of the sheet is dipped into electrolyte and serves to siphon the electrolyte onto the sheet where it ows downward under the influence of gravity.

The lower end of the sheet is serrated to form a plurality of drip points. These drip points feed the separated components of the sample into collecting vessels.

Many expedients have been employed for applying a transverse electric eld to the anticonvection medium. In apparatus where a sheet of lilter paper is employed as the anticonvection medium, tabs have been formed at the bottom on opposite edges of the sheet. These tabs are adapted to dip into electrode vessels. The resulting electric field is not uniform along the length (vertically) of the sheet. Generally, the eld is many times stronger at the bottom than at the top of the sheet. This results in a greater separation of the components of the sample for an equal distance of travel at the bottom of the sheet than near the upper margin. The most desirable configuration of the field is achieved when the components follow essentially straight paths along the length of the sheet.

In some apparatuses metallic electrodes areintroduced along the side of the curtain. These electrodes are `usually formed of platinum, carbon or other non-corrosive material. However, electrode products are formed next to the electrodes and nd their way into the main body of the curtain. This serves to distort the pattern and in some instances to prevent the separation of the mixtures. To overcome this diculty, a semipermeable membrane has been disposed between the curtain and the electrodes. In the past, electrolyte has been forced past the electrode and when laminar flow is achieved the electrode products are washed away and yet a competent electrical circuit is made between the electrode and curtain.

It is a general object of the present invention to provide an improved continuous electrophoresis apparatus.

It is'a further object of the present invention to provide a novel means for making electrical contact to the side margins of the anticonvection medium.

y 2,879,217 Patentedl Mar. 24, 1959 It is a further object of the present invention to provide a control system which is adapted to easily balance the flow down the central portion of the curtain with respect to the ow down the edges of the same.

It is a further object of the present invention to provide a control system in which the ow along the side edges of the curtain may be controlled independently of the flow down the central portion of the curtain whereby the pattern may be compressed or tilted, a's desired.

It is a further object of the present invention to provide a novel meansl for applying a sample to the upper margin of the anticonvection medium.

It is a further object of the present invention to provide a continuous electrophoresis apparatus in which the tlow of electrolyte down the main curtain may be easily controlled.

It is a further object ofthe present invention to provide a continuous electrophoresis apparatus in which columnar electrolytic bus bar wicks make electrical contact with the side margins of the main curtain.

It is a further object of the present invention to provide a continuous electrophoresis apparatus in which columnar wicks are adapted to make electrical contact with the side margins of the main curtain and in which means are provided for independently and controllably supplying electrolyte to the top of the wicks.

These and other objects of the invention will become more apparent from the following description and laccompanying drawings.

` Referring to the drawings:

Figure 1 is a front elevational view of a continuous electrophoresis apparatus constructed in accordance with our invention;

Figure 2 is a side elevational view of the apparatusof Figure 1;

Figure 3 is a sectional view taken generally along the line 3 3 of Figure 1;

Figure 4 is a partial sectional elevational view showing the relationship of the electrolyte reservoir, feed curtain, main curtain and other parts of the apparatus;

Figure 5 is a sectional yView taken generally along the line 5-5 of Figure 3; f

Figure 6 is a sectional view taken along the line 6-6 of Figure 1;

Figure 7 is a schematic view showing the electrode vessels which receive the electrodes and apply a potential thereto; and

Figure 8 is a plan view of the electrolyte reservoir.

.Referring to Figures 1 and 4, the intermediate portion of. thefeed curtain 11 is supported by the wall of the electrolyte reservoir 12. The two end portions hang downward on opposite sides of the wall. One en d dips into the electrolyte 13 and the other end is disposed above the main curtain, to be presently described. The feed curtain is made oflsuitable anticonvection material, for example, tilter paper, which serves to Siphon electrolyte 13 from the reservoir as indicated by the arrow 14. The electrolyte travels by gravity downward and drips from the drip points 16 which may be formed by serrating the end of the curtain 11. Asv will be presently described, the amount of electrolyte siphoned by the feed curtain may be controlled.

The serrated edge may be held by rods 17 and 18 (Figures l, 2 and 4) which hold the end of the feed curtain therebetween. The rods extend across the apparatus and have their ends'accommodated within slots 19. The slots 19 are formed in the members 21 which are suitably attached to the tank assembly, as will be presently described.

The main curtain 22 which is made of suitable anticonvection material, for example, lter paper is supported by the rod 23 and has its upper portion held between the members 24 and 25 which may be clamped together by means of screws 26. The rod 23 and the members 24 and 25 extend across the apparatus and are suitably attached to the spaced side members 27. A pair of pins 28 and 29 are suitably attached to the other side of each of the members 27. The pins are adapted to ride in the accommodating groove 31 which is formed in the reservoir assembly.

The bottom end of the curtain 22 is provided with a plurality of tabs 33 which are formed by serrating the bottom edges. For greater resolution, the tabs 33 are split to form portions 34 and 35. The portions 34 and 35 extendover opposite sides of the rod 36. The rod 36 is attached to the members 37 which are suitably attached to the base 38.

The base 38 is formed with an opening 39. A member 40 is suitably attached to the base. The receiver member 41 is carried by the member 40. The member 41 is bored to form a plurality of funnel-like openings 42. These openings are spaced along the apparatus to correspond to the spacing of the tabs 32 with a pair of openings formed below each drip point whereby the components appearing at the front portion of the tab 33 and the rear portion 34 will drop into separate openings. Suitable tubes 43 are attached to the receiver 41 and extend downwardly through the base of the apparatus.

A rack 44 carries a plurality of collecting vessels or tubes. The rack is placed under the apparatus whereby the separated components will drip into the respective tube 46.

The reservoir assembly is U-shaped in plan view (Figures 3 and 8) and is supported by the-back wall 51 of the housing. A transverse mem-ber 52 is suitably attached to the back wall 51 and has its upper edge bevelled 53 whereby a groove is formed. A transverse member 54 is attached to the back wall 56 of the reservoir 13 and has its lower edge bevelled to form the projection 57 which is accommodated within the transversev groove. An abutment 58 is formed on the bottom portion of the reservoir assembly and serves to lbear against the wall 51. Thus, the reservoir assembly is supported within the housing by the members 52 and 54.

The reservoir extends outwardly at the endsv to form the aforementioned U-shaped reservoir. Referring more particularly to Figuresl and 4, the end portions are shown. These end portions have side walls 61. The inner wall is suitably attached to the front wall 62 of the transverse portion of the reservoir. A wall 64 forms the forward wall of the forwardly extending side portions. The groove 31 previously described is formed on the inside of the forwardly extending portion ofthe reservoir. The member 21, also previously described, is suitably attached to the inside surface. As previously described, the upper portion of the wall 62 serves to support the feed curtain 11 which is disposed between the outwardly extending end portions of the reservoir. 1 t

The ow of electrolyte down the feed curtain 11 may be controlled in several ways. For example, if lter paper is used, various types are available, which have different degrees of porosity and thickness. In general, thick coarse papers afford more rapid ow (and poorer resolution, as will be presently described) than thinner more compact papers. The llow of background electrolyte down the paper may also be controlled by varying the liquid level in the electrolyte reservoir with respect to the height of the upper edge. It is also possible to serrate the edges which tip into the electrolyte to control the flow.

The adjustable stand pipe 66 (Figuresl 3 and 5) provides means for controlling the level of the liquid 13. Referring more particularly to Figure 5, the stand pipe-66 is received within the sleeve 67. Suitable lubricant may be applied to the pipe 66 to minimize leakage of electrolyte. The lower portion of the stand pipe 66 is held by the me1nber 68 which is attached to the threaded member 69.

A gear 71 engages the threads of the member 69. The gear 71 is mounted on the shaft 72 which is rotated by the knob 73, which is located outside the side wall 74. By rotating the knob 73, the stand pipe 66 may 'be raised and lowered to control the electrolyte level. The overftow electrolyte travels down the pipe 66, as indicated by the arrow 74 (Figure'3) and ows into the reservoir 76. An opening 77 is formed at the bottom of the reservoir and extends through the side wall 74 of theapparatus, as illustrated in Figure l. The overow electrolyte ows downward through a suitable tube 78 and may be returned to the electrolyte supply tank (not shown).

Fluid may be continuously pumped from the tank by a pump (not shown), up through the pipe 79 (Figures 2 and 3), which is located at the rear of the apparatus through the back wall, down the tubing 81, into the reservoir. The fluid may also be caused to flow into thereservoir from an elevated tank by gravity. The amount of uid pumped into the reservoir is greater than the amount which is siphoned from the reservoir by the curtain and other means to be presently described. Thus, there is a constant flow of liquid down the stand pipe whereby the level of the liquid 13 in the reservoir is always maintained for any position of the stand pipe.

At some position `at the top of the filter paper forming the main curtain a tab is produced lby cutting the curtain and bending it forward. The mixtureto be separated is continuously fed to the tab 82 by suitable means. For example, a filter paper wick may be employed. However, we prefer to employ a feed which depends upon the difference in height between the tab and the liquid contained in a vessel to control the rate at which the liquid is fed onto the tab. Thus, the mixture 83 to be separated' is disposed in a vessel 84. A tube 85 serves to connect the lower end of the vessel with the feed member 87. Suitabley clamps 88 engage the top of the vessel 84. The clamps are xed to a member 89 which is carried on the end of the rod 91. The rod 91 is suitably driven by motive means (not shown) at a constant ratewhereby the vessel 84 is continuously raised. For example, the lower end of the rod 91 may have a rack formed thereon. A pinion gear which may be driven at a constant rate is adapted to engage the rack to drive the rod. The pinion gear may be connected directly to a motor or to a variable speed drive. By suitably choosing the inner diameter of the tube 8S and the rate at which the vessel is raised, the mixture can be fed to the curtain 22 at suitable constant rates. The feed member 87 is carried by the carrier 92. The carrier 92 is mounted on the member 93 which is suitably attached, for example, by means of screws 94 to the member 19 previously described. Thus, the lateral position of the member 87 may be adjusted by sliding the carrier 92 on the transverse member 93. As previously described, the tabs may be formed at any suitable location along the top of the curtain 22. The location of the tabs depends, among other things, upon the mixture to be separated and background electrolyte.

As previously pointed out, in continuous electrophoresis apparatus an electric tield having a component which is transverse to the flow of the background electrolyte is employed to elect the separation of the components of the mixture. According to the invention, columnar electrolytic bus bar wicks 96 are employed to apply the electric field to the curtain. The bus bar wicks may be made of absorbent material. They are adapted to contact with the side margins of the curtain to supply an electric potential across the same. A suitable columnar bus bar wick may be formed by stacking a plurality of elements 97 which are made of the same type of material as the curtain 22. Referring particularly to Figure 6, the elements 97 are shown stacked in the U-shaped member 98. A clamping plate 99 is secured to one edge to the member 9,8 by means of screws 101. The other edge has a member 102 which presses the curtain 22 against the adjacent surface of the wick 96. Referring coil electrode may be vdipped into the electrolyte.

more particularly to Figure 1,`tl1e clamping plate 99 is shown extending along the edge of the curtain 22. The bus bar wick extends along side of the curtain 22 engaging the same over the major portion thereof. The lower end of the wick 96 extends beyond the curtain and dips into the electrolyte 103 of the electrode container 104.

The U-shaped member which serves to hold the wick may be suitably attached to the side walls. For example, the member may be provided with a pair of plates of the -type employed to hold the electrolyte reservoir which -amount of material which is comparable to the curtain whereby the electric eld applied to the curtain is relatively uniformly lengthwise of the curtain. That is, the main curtain acts as the central portion of an equivalent curtain which is many times wider.

Suitable means are provided for independently and controllably feeding electrolyte to the top of the bus bar wicks which extend along the side margins of the curtain.

By controlling the ow of electrolyte in the wicks, the

iiow rate down the central curtain may be made uniform across the same. Further, if the flow of electrolyte on the wicks is increased beyond a certain point, electrolyte will flow inward from the wick to the curtain and thereby serve to increase the ow of electrolyte on the side edges of the curtain. There will be a more rapid flow of electrolyte on the sides than in the center. As aresult, the pattern is compressed. By unbalancing the electrolyte fed onto the wicks, the pattern may be tilted either to the left or to the right. By increasing the ow of electrolyte on the right side and decreasing the iiow on the left side, serving to withdraw electrolyte from the curtain, the pattern will be tilted to the left and vice versa. By reducing the electrolyte ow in the wicks, electrolyte flowing down the curtainy will ow outward into the wicks and the pattern is expanded.

The electrolyte is siphoned from the main reservoir by capillary U-tubes 108 (Figures 1, 2 and 3) which have one end dipping into the reservoir electrolyte 13 and the other end extending over the wall 64. The U-tube serves to siphon the uid into the passage 109, The ilud travels through the passage 109 to the drip point 111 onto the upper end of the columnar wicks. The electrolyte travels downward into the container 104 providing a backwash. The level of uid in the container is maintained constant by means of the overflow gate 112.

When the ow down the central portion of the curtain with respect to the flow down the edges of the same is equalized by appropriately adjusting the height of the U-tubes associated with the columnar wicks, the field applied across the curtain is approximately two times as strong at the -bottom of the same as at the top. However, the conductivity of the'electrolyte increases from top to bottom due to evaporation of electrolyte from the curtain. The result is that the field lengthwise of the curtain is substantially uniform and the components are eiciently separated. The resulting pattern shows bands which deviate in approximately straight lines from the point of application of the sample.

To wash away electrode products which might migrate or siphon up along the electrode and into-the main curtain, it may be desirable to provide additional backwash. Thus, a tube 113 has its upper end U-shaped and dips into the reservoir to siphon uid 13 therefrom. The uid 13 travels down the tube 113 adjacent the portion of the electrode dippinginto the iiuid 103...This causes a ow Vof iluid across the electrode, past the baies 114 and 11S and 116 and out over the gate 112, as roughly indicated by the arrows 117. The overflow iluid travels along the base 38 through outlet 118.

The amount of fluid siphoned by the U-tube 108 may be controlled by raising and lowering the tube. Thus, a member 119 vis secured to the upper end of the threaded .member 121. The end `of the member 119 engages the U-tube to hold the same. A gear (not shown) rotated by the knob 122 engages the threaded member. A graduated scale 123 is provided on the side of the apparatus and a marker 124 serves to indicate the position of the U-tube. Thus; 'the apparatus may be vcalibrated antd a predetermined position set by rotating theknob 122 whereby the predetermined amount of electrolyte ows down the elec- .trode 96.

The enclosure previously referred to includes a back member 51, side members 74, a top member 126 and the front panel 127. The front lpanel 127 is removably secured to the cover. Thus, thumb screws 128 are adapted to engage the member'129 which extends around the apparatus. The bottom of the front plate 127 is en gaged in the transverse slot 131. The container 104 is removably mounted within the apparatus. Thus, when the electrode is removed, the container 104 may be drawn outwardly from therear by disengaging the plug 133.

Generally,.the front portion of the housing is made of clear plastic and the apparatus is operated at temperatures which might cause condensate to form on the inner surface and to impair visibility into the apparatus. Thus, means are provided to collect the vapors and condense the same adjacent the curtain 22. Such a heat exchanger may comprise zigzag coils. Preferably, we employ spaced plates with baiiles. For example, the apparatus may comprise space plates 141 and 142 which are provided with a series of bales 143. Alternate bailes are secured to one side, while others are secured to the opposite side whereby a zigzag path is formed such as shown in Figure 5. Thus, the cool liquid enters at 144, travels to the right in Figure 5, over the end of the bafe and back toward the left past the end of the bale 146, etc., and leaves at the bottom 147. The condensate which collects on this cooling plate drips off the drip member 148 to the bottom of the apparatus and out through the opening 118, as previously described.

Operation of the apparatus` is as follows: The curtain 11 is placed with its one end immersed in the electrolyte and with the serrated end between the rods 17 and 18. The main curtain 22 is placed over the rod 23 and clamped 'between the members 24 and 25. The main curtain is clamped to make contact with the electrodes 96 by means of the member 99. Fluid is continuously pumped into the reservoir and the level of the stand lpipe is adjusted whereby the desired amount of electrolyte is siphoned o'nto the main curtain by the feed curtain. Liquid is siphoned by the U-tubes 108 onto the electrode. A voltage is applied across the electrodes.

The apparatus is yallowed to operate until a steady state has been reached and until the electrolyte owed on the main curtain is uniform. To equalize the ow on the sides of the curtain, the amount siphoned by the pipes 108 is controlled. When a steady state has been reached and the desired amount of electrolyte is flowing down the curtain, the mixture is added to the tube 84 and fed onto the tab 82 where it travels downward with the background electrolyte. The mixture is separated by the electric eld as previously described. The tube 84 is raised at a predetermined rate whereby the rate at which the mixture is fed onto the curtain is maintained constant. The separated components are collected by the tubes 96 disposed beneath the apparatus.

Apparatus was constructed asdescribed. The main curtain was 14" wide and approximately 16" long and was cut from Schleicher & Schuell Grade 470 filter paper. Thirty-two drip points were formed at the lower edge thereof. Each of the columnar electrolytic wicks were formed by stacking twenty-two strips of tlter paper measuring 2 by 13%.".

The electrolytic solution pumped into the reservoir was of 0.02 ionic strength barbital buffer (pH 8.6). The apparatusA was maintained in an ice box, which was held at 1 C. A constant current' of 30 milliamperes was caused lto flow across the curtain by application of 500 v. at the electrodes from a constant-current type power supply. Under theseconditions, the curtain temperature was 7 C` A sample ofv human serum which had been previously dialyzed against the electrolyte solution was'continuously fed to the curtain from a tab 4" from the negative side of the curtain just below the. support rod at a rate of approximately 1.5 ml. per hour. After the curtain had come to equilibrium, samples were collected from the drip points which were numbered l-32 from the negative toward the positive side of the curtain.

The experiment was completed in approximately twentyfour hours and the material collected in the tubes corresponding to the tabs was examined. Protein was present in tubes 7 through 26 inclusive. The samples in these tubes were concentrated by dialysis against a 30% polyvinyl pyrrolidine solution and then subjected to electrophoresis on lter paper in a strip apparatus. Subfractions of gamma globulin were present in tubes 7-12, while sub-fractions of beta globulin werek present in tubes 13-17. Alpha 2 globulin sub-.fractions were present in tubes 18 through 21 and alpha 1 globulin sub-fractions in tubes 22, 23 and 24. Albumin was present in tubes 24, 25 and 26. Beta lipoproteins were present in tubes 17 through 21; tube 22 was free of lipoprotein, while tubes 23, 24 and 25 contained alpha lipoprotein.

Thus it is seen that we have provided an improved electrophoresis apparatus in which the components of a sample containing the same are eflciently separated. The apparatus includes means whereby the flow of electrolyte down the main curtain may be equalized across the same. The flow of electrolyte applied on the main curtain may also be varied whereby the side edges have either more or less electrolyte owing therein than the central portion. By varying the flow of electrolyte, it is possible to compress or tilt the pattern as desired.

We claim:

l. A continuous electrophoresis apparatus for the sepa- .ration of components from a material` sample containing the same comprising an anticonvection curtain-like medium adapted to have background electrolyte fed thereto, means for continuously feeding. a liquid Kbackground electrolyte to the upper margin of said medium, means for applying said material sample to said curtain in a region near the said upper margin, means forming columnlike electrolytic Wicks inconductive contact with the side margins of the medium, said wicks each comprising a column of absorbent material indirect physical contact with said medium along a substantial length of the side margin of the same, means for continuously applying a liquid electrolyte to the upper ends of the column-like wicks, and means for making electrical connection to the bottom of said columns whereby a transverse electric field is applied to said curtain-like medium.

2. Apparatus as in claim 1 wherein said curtain-like material comprises a sheet of lter paper.

3. A continuous electrophoresis apparatus for the separation of components from a material sample containing the4 same comprising an anticonvection curtain-like medium adapted to have lbackground electrolyte fed thereto, kan electrolyte reservoir disposed above said medium, means for continuously siphoning electrolyte from said reservoir and feeding the sameL to the upper margin of said medium, means for applying said material sample to said curtain in a region near the upper margin, means forming column-like electrolytic bus bar wicks in conductive contact with `the side margins of` the medium,

said wicks each comprising a column of absorbent material making direct physical contact withr the curtainlike medium along substantially the full length of the side margin of 'the same, means for continuously supplying a liquid electrolyte to the upper ends of said columns from said reservoir, and means for making electrical connection to the bottom of said column-like wicks whereby a transverse eiectric eld is applied to said curtain-like material.

4. A continuous electrophoresis apparatus for the separation ofcomponents from a materialsample containing the same comprising Van antconvection curtain-like medium adapted to have background electrolyte fed therevoir andv feeding the same to the upper margin of said medium, means for applying said material sample to v said curtain-like medium in a region near the upper margin, means forming column-like electrolytic wicks in conductive contact with the side margins ofthe medium, saidi wicks each comprising a column of absorbent material making direct physical contact with said medium along substantially the full length of the side margin of the same, means for continuously siphoning electrolyte from said reservoir to the upper ends of the columns, electrode vessels disposed beneath said columns and adapted to maintain electrolyte at a predetermined level to maintain the lower ends of said columns immersed, and means for making electrical connection to the electrolyteV in said vessels whereby an electric potential is applied to the bottom of said columns and applied transversely across said medium.

5. Apparatus as in claim 4 including means serving to siphon electrolyte from said reservoir into said electrode vessels to thereby enhance the washing away of electrode products formed in the vicinity of the columnlike electrodes.

6. Apparatus as in claim 4 wherein said means for siphoning electrolyte from said reservoir to the upper ends of said columns comprises U-tubes, and means for controlling the height of said tubes whereby the rate at which electrolyte is fed onto the wicks may be independently controlled.

7. A continuous electrophoresis apparatus for the separation of components from a material sample containing the same comprising an anticonvection curtain-like medium adapted to have background electrolyte fed thereto, an electrolyte reservoir disposed above said kmedium, means for continuously siphoning electrolyte from said reservoir and applying the same to the upper margin of said medium, means for applying the said material sample to said curtain in a region near the said upper margin, means forming column-like electrolytic wicks in conductive contact with the side margins of the medium, said wicks each comprising a columnof absorbent mate'- rial having direct physical contact with said medium along'substantially the full length of the side marginsV of the same, means for continuously applying a liquid electrolyte to the upper ends of the columns, means 4for making .electrical connection to the bottom of the columns whereby a transverse electric eld is applied to the curtain, and means extending into said reservoir and adapted to be y set at a predetermined height to maintain the reservoir electrolyte at'a predetermined level.

8. A continuous electrophoresis apparatus for separation of components from a material sample'containing the vsame comprising an anticonvection curtain-like medium adapted to have background electrolyte fed thereto, means for continuousuly feedinga liquid background electrolyte to the upper margin of said medium, means for applying said material sample to said curtain a region near the upper. margin, means forming column-like electrolytic wicks in conductive contact with the said margin of the medium, said wicks each comprising a column of absorbent material. in. direct` physical contactv with said medium along a substantial length of the side margin of the same, means for independently and controllably applying a liquid electrolyte to the upper ends of said columns, and means `for making electrical connection to the bottom of said columns whereby a transverse electric eld is applied to said curtain-like medium.

9. Apparatus as in claim 8 wherein said means for independently and controllably applying an electrolyte to the upper ends of the wicks are independently controlled.

10. A continuous electrophoresis apparatus for the separation of components from a material sample containing the same comprising an anticonvection curtainlike medium adapted to 'have background electrolyte fed thereto, an electrolyte reservoir disposed above said medium, means for continuously siphoning electrolyte from said reservoir and feeding the same to the upper margin of said medium, means for applying said material sample to said curtain in a region near the upper margin, means forming column-like electrolytic wicks in conductive contact with the side margins of the medium, said wicks each comprising a column of absorbent material making direct physical Contact with the curtain-like medium along substantially the full length of the side margins of the same, means associated with each of said Wicks for continuously supplying a liquid electrolyte to the upper ends of said column from said reservoir, means for independently controlling said means serving to apply electrolyte to the wicks whereby the ow of electrolyte onto said wicks may be independently controlled, and means for making electrical connection to the bottom of said column whereby a transverse electric field is applied to the curtain-like material.

1l. A continuous electrophoresis apparatus for the separation of components from a material sample containing the same comprising an anticonvection curtain-like material adapted to have background electrolyte fed thereto, an electrolyte reservoir disposed above said medium, a

feed curtain continuously siphoning electrolyte from said i reservoir and applying the same to the upper margin of said medium, means for applying said material sample to said medium in a region near the upper margin, means forming column-like wicks in conductive contact with the side margin of the medium, said wicks each comprising a column of absorbent material having direct physical contact with said medium along substantially the full length of the side margins of the same, U-tubes having one end immersed in the reservoir electrolyte and the other end adapted to feed electrolyte onto the upper ends of said wicks, means associated with each of said U-tubes for independently moving the same vertically whereby the rate at which electrolyte is siphoned from said reservoir onto the column-like wicks may be independently controlled, and means for making electrical connection to the bottom of said columns whereby a transverse electric eld is applied to said curtain-like material.

12. A continuous electrophoresis apparatus for the separation of components from a material sample containing the same comprising a sheet of lter paper adapted to have background electrolyte fed thereto, means for continuously feeding a liquid background electrolyte to the upper margin of said lter paper, means for applying said material sample to said lter paper in a region near said upper margin, column-like electrolytic wicks placed in direct physical and conductive contact along a substantial length of the side margin of the filter paper, said wicks each comprising a plurality of strips of lter paper stacked one on top of another, means for continuously applying a liquid electrolyte to the upper ends of the column-like wicks, and means for making electrical connection to the bottom of said column-like wicks whereby a transverse electric field is applied across said lter paper.

References Cited in the le of this patent FOREIGN PATENTS Great Britain Oct. 13, 1954 

1. A CONTINUOUS ELECTROPHORESIS APPARATUS FOR THE SEPARATION OF COMPONENTS FROM A MATERIAL SAMPLE CONTAINING THE SAME COMPRISING AN ANTICOVENCTION CURTAIN-LIKE MEDIUM ADAPTED TO HAVE BACKGROUND ELECTROLYTE FED THERETO, MEANS FOR CONTINUOUSLY FEEDING A LIQUID BACKGROUND ELECTROLYTE TO THE UPPER MARGIN OF SAID MEDIUM, MEANS FOR APPLYING SAID MATERIAL SAMPLE TO SAID CURTAIN IN A REGION NEAR THE SAID UPPER MARGIN, MEANS FORMING COLUMNLIKE ELECTROLYTIC WICKS IN CONDUCTIVE CONTACT WITH THE SIDE MARGINS OF THE MEDIUM, SAID WICKS EACH COMPRISING A COLUMN OF ABSORBENT MATERIAL IN DIRECT PHYSICAL CONTACT WITH SAID MEDIUM ALONG A SUBSTANTIAL LENGTH OF THE SIDE MARGIN OF THE SAME, MEANS FOR CONTINUOUSLY APPLYING A LIQUID ELECTROLYTE TO THE UPPER ENDS OF THE COLUMN-LIKE WICKS, AND MEANS FOR MAKING ELECTRICAL CONNECTION TO THE BOTTOM OF SAID COLUMNS WHEREBY A TRANSVERSE ELECTRIC FIELD IS APPLIED TO SAID CURTAIN-LIKE MEDIUM. 